KING DIAMOND's North American headlining tour — which is scheduled to launch March 23 in Lake Buena Vista, Florida, and run through May 8 in Houston — has been cancelled due to a herniated disc.

"I can't sit down, even on my couch, for more than a few minutes," King recently told MTV.com. "About [two months ago] I tried, and after 15 minutes, it started feeling like my left leg was getting set on fire."

"It can take up to a year and a half for a severe herniated disc to heal properly, but it varies from person to person," he added. "Right now there's not much more we can do."

Diamond got a taste of what might happen if he hits the road too soon in September when director Bill Schacht from video company Aestheticom — which has also worked with AMON AMARTH — shot a video for "Give Me Your Soul", the first KING DIAMOND clip in 17 years. "They limited what I had to do, of course, so I only did one day of shooting for 90 minutes, but just standing there moving a little bit in the full outfit was very difficult," he said. "And afterwards, I got one of those sharp attacks of pain that I hadn't had in a month and a half. The only thing I can compare it to is a really super-bad toothache or earache. And afterwards, I was like, 'OK, I'm not ready [to tour] yet.' "

Regarding how he injured his back, the 51-year-old singer said, "I think the real damage happened mixing the record, because I did that three weeks straight for a minimum of 12 hours a day. One of the last nights, when I was going to bed, I felt these pains in the sciatic nerves on each side, and I thought, 'Oh what is this?' The next morning I woke up and I couldn't walk or stand. It was like being paralyzed. I can't begin to say how painful it was. They say that's the worst pain you can experience as a human being. Had I not lived on the ground floor in a house, I would have jumped out the window."